JPH1181387A - Lower travelling body of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a swivel joint by installing a intake-exhaust path for a travelling motor communicating the swivel joint and the travelling motor and having a pressure-oil diverging means and a intake- exhaust path for an actuator for operation communicating the pressure-oil diverging means and the actuator for operation. SOLUTION: Intake-exhaust paths 64, 77, 64', 77' for travelling motors 6L, 6R are mounted as main pressure-oil feed paths passing through a swivel joint 36, main pressure oil fed to a dozer cylinder 8 as a hydraulic actuator for operation is supplied through a flow dividing valve 44 from a pipeline communicating the swivel joint 36 and the travelling motors 6L, 6R, and a changeover valve 37 for a dozer controlling the flow dividing valve 44 and the dozer cylinder 8 is arranged to the lower travelling body 1 in the vicinity of the swivel joint 36. Since only the intake-exhaust paths 64, 77, 64', 77' for the travelling motors 6L, 6R are set up as main pressure-oil feed paths passing through the swivel joint 36, the occupied space to a car body of the swivel joint 36 is minimized, and manufacturing cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower traveling body of an upper swing type construction machine such as a hydraulic shovel.

[0002]

2. Description of the Related Art FIG. 4 is a hydraulic circuit diagram of a wheel type power shovel disclosed in Japanese Utility Model Laid-Open No. 58-59859. The upper turning frame side (11a) of the hydraulic circuit (11) shown in FIG. 4 has a hydraulic source (12) composed of an oil tank (13), an engine (14), gear pumps (15) and (16), and a pipe connected thereto. One set of the control valve group (17) is constituted by a control valve group (17) connected to the road, and the control valve group (17a) for operating the outrigger and one of the control valve group (17a) are used as well as the other set. Is the control valve (17b) for operating the other outrigger, and both control valves (17
a) and (17b) are operating levers (1) provided in the driver's seat.
8) and (19) are operated.
The control valves (17a) and (17b) have the first
Pipelines (20), (20) and second pipelines (21), (2)
1) is followed by the first conduits (20), (20) and the second
Pipes (21), (21) are swivel joints (2
2) It is connected to the first port (23) and the second port (24). On the other hand, the lower traveling body side (11b) of the hydraulic circuit (11) is provided with a switching valve (25) for connecting the first port (23) and the driving cylinders (5), (5) of the earth discharging plate. A third conduit (26), (26);
The switching valve (25) in the pipelines (26), (26)
And a switching valve (2) branched from between the first port (23) and connected to the driving cylinder (7) of one outrigger.
7) a fifth pipeline (29), which connects the fourth pipeline (28), (28) with the second port (24) and the driving cylinder (9) of the other outrigger. 29).

FIG. 5 shows an operation lever (30) for operating a handbrake and a switching valve (25) in FIG.
It is a partially notched front view which shows the relationship with (27). As shown in FIG. 5, the two switching valves (25) and (27) are moved up and down through a central portion of the swivel joint (22) by an operation lever (30) provided in a driver's seat and also serving for handbrake operation. Exercise towbar (31) and link (32)
The switching operation is performed by a) and (32b).

[0004]

2. Description of the Related Art Conventionally, a hydraulic excavator is equipped with a traveling motor on a lower traveling body and, for example, mounted with an earth discharging plate (also referred to as a dozer blade). In the wheel type power shovel according to one embodiment of the prior art shown in FIGS. 4 and 5 (the entire external view is not shown),
Driving cylinders (5) and (5) for the earth discharging plate, driving cylinder (9) for the outrigger, and a traveling motor for driving wheels (wheels) (not shown in FIG. 4, but a central portion of the swivel joint 22) Since the tow bar 31 is passed through the hole, it was determined that the propeller shaft for mechanical traveling drive was not used.) For this purpose, a number of passages for supplying the main hydraulic oil to the plurality of hydraulic actuators must be provided in the swivel joint (22). Since the flow rate of the pressure oil passing through each of the multiple passages is large, the cross-sectional area of each passage is considerably large, and the shape of the swivel joint (22) becomes large. As a result, the swivel joint (22) occupies a large space in the vehicle body, and the manufacturing cost of the swivel joint increases, resulting in poor cost. Conventionally, a hydraulic excavator has an engine, hydraulic equipment, a driver's cab, and the like mounted on an upper revolving structure. Therefore, a severe restriction is imposed on a layout in consideration of maintenance such as inspection and repair. In the wheel type excavator according to the prior art shown in FIG. 5, since the control valves (17a) and (17b) are provided on the upper revolving structure, the layout and maintenance thereof become difficult. In the present invention, the passage of the main pressure oil passing through the swivel joint is set only in the supply / discharge circuit for the traveling motor, and the control valve of the working hydraulic actuator mounted on the lower traveling body other than the traveling motor is arranged on the lower traveling body. It is an object of the present invention to provide a lower traveling body of a construction machine configured to perform the operation.

[0005]

According to the present invention, an upper revolving unit is connected to an upper portion of a lower traveling unit, and pressure oil from a hydraulic pump mounted on the upper revolving unit is distributed to the lower traveling unit via a swivel joint. In a construction machine configured to supply the traveling motor and a working hydraulic actuator provided, a supply / discharge passage for the traveling motor that communicates the swivel joint and the traveling motor, and a pressure provided in the supply / discharge passage for the traveling motor. An oil distribution unit and a work actuator supply / discharge passage communicating the pressure oil distribution unit and the work actuator are provided. In the above case, the pressure oil dividing means and the work actuator direction switching valve provided in the work actuator supply / discharge passage are arranged on the lower traveling body.

In the present invention, only the supply / discharge passage for the traveling motor is provided as the main pressure oil supply passage having a relatively large cross-sectional area passing through the swivel joint. Therefore, the space occupation of the swivel joint in the vehicle body is minimized. And the manufacturing cost of the swivel joint can be reduced. Further, since the pressure oil dividing means and the directional control valve for the working actuator are arranged on the lower traveling body, the piping connected to the swivel joint can be shortened, and a compact coupling arrangement can be achieved. Layout and maintenance can be performed with a margin. In addition, since the passage for passing the swivel joint in a passage other than the supply / discharge passage for the traveling motor is, for example, a pilot pressure passage or a drain passage having a relatively small cross-sectional area, the shape of the swivel joint can be made compact. ,
The switching operation of the work actuator direction switching valve can be easily performed without any trouble.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a hydraulic excavator 2 having a lower traveling body 1 according to an embodiment of the present invention. In FIG, 3 is an upper revolving structure which is articulated on the lower traveling body 1, 4 is working attachment mounted on the front portion of the upper turning body 3, 6 _L, 6 _R is traveling pair provided on the lower traveling body 1 motor (left traveling motor 6 _L is not visible in the figure), 8 dozer cylinder for dozer device 10, 33 is a boom cylinder, 34 an arm cylinder,
35 is a bucket cylinder. FIG. 2 is a hydraulic circuit diagram of the excavator 2 in FIG. In the figure, 36
Reference numeral 44 denotes a swivel joint, which is a swivel joint for exclusively connecting the hydraulic passage on the upper revolving unit 3 side and the hydraulic passage on the lower traveling unit 1 side, and 44 denotes a diversion valve (flow divider and 45 is a switching valve for selection in the flow dividing valve 44, 37 is a switching valve for dozer which is a directional switching valve for controlling the dozer cylinder 8 (also called a normal control valve), 46, 47, and 46. 48 is a relief valve attached to the dozer device 10 and 49 is a
Are the pilot ports 50 on the left and right of the dozer switching valve 37.
_L , 50 _R , a hydraulic pressure remote control valve for dozer, which derives a switching command pilot pressure and operates the dozer cylinder 8, 51
Is a dozer work mode commanding electromagnetic switching valve which is a command switching valve for setting the hydraulic circuit to the dozer work mode by turning on the switch 52 when the traveling of the hydraulic excavator 2 and the dozer device 10 are performed simultaneously. , 39
_L, 39 _R is traveling directional control valve for controlling a travel motor 6 _L, 6 _R of left and right, each of the first to discharge the main pressure oil 40,41, the second pump, the pilot 43 is the pilot hydraulic source The pump 54 is an oil tank.

When a hydraulic excavator 2 (shown in FIG. 1) equipped with a hydraulic circuit shown in FIG. 2 performs a dozer operation,
The switch 52 is turned on in advance. Electromagnetic switching valve 51 for dozer work mode command (hereinafter referred to as electromagnetic switching valve 51)
Is switched from the tank communication oil passage position G to the open oil passage position G. The pilot pressure from the pilot pump 43 acts on the pilot port 62 of the selection switching valve 45 through the H position of the electromagnetic switching valve 51, the pipe 59, the pilot pressure passage 60 in the swivel joint 36, and the pipe 61. The selection switching valve 45 switches from the traveling motor supply oil passage position E to the distribution oil passage position. In this case, the left and right traveling direction switching valves 39 _L ,
When the 39 _R is switched to the earth discharging progress positions A and A ′, the pressure oil from the first pump 40 and the second pump 42
Each of the pipes 63 and 63 ′, the main pressure supply passages 64 and 64 ′ in the swivel joint 36, the pipes 65 and 65 ′, and the diverting oil passage position of the selection switching valve 45 diverges inside the diverting valve 44. Via the control unit 66, the flow dividing valve 4
4 are diverted from the left and right output ports 56 _L and 56 _R for the traveling motor and the output port 67 for the dozer cylinder. Thereby, the left and right traveling motors 6 _L and 6 _R rotate, and the hydraulic excavator 2 travels. And in this case, the pressure oil led out from the dozer cylinder output port 67 is:
Since the dozer switching valve 37 is in the neutral position, the relief operation of the relief valve 46 connected to the supply pipe 68 causes the oil tank 54 to pass through the pipes 69 and 70 and the tank communication passage 71 in the swivel joint 36 and then to the oil tank 54. Returned to When the dozer hydraulic remote control valve 49 is operated in this running state, the pilot pressure derived from the dozer hydraulic remote control valve 49 is changed to the pilot pressure passage 73 or 7 in the swivel joint 36 by the pipeline 72 or 72 ′.
3 ', dozer switching valve 3 through line 74 or 74'
7 together with the dozer switching valve 37 which acts on the pilot port 50 _L or 50 _R is switching operation of a relatively low flow rate of the hydraulic fluid derived from dozer cylinder for the output port 67 of the diverter valve 44, the switch valve dozer Since the dozer cylinder 8 is supplied through the 37 switching positions, the earth discharging plate can be operated at an optimum speed.

Next, FIG. 3 shows the hydraulic excavator 2 shown in FIG.
FIG. 2 is a plan view of a main part of an incision showing the lower traveling body 1 of FIG. In the drawing, reference numeral 75 denotes a car body frame of the undercarriage 1, 76
_L, 76 _R is a pair of left and right crawler frames.

Next, the structure of the undercarriage 1 of the present embodiment will be described with reference to FIGS. In the present embodiment, supply and discharge passages of the traveling motor 6 _L, 6 _R as a main pressure oil supply passage through the swivel joint 36 as shown in FIG. 2 64,7
7, 64 ′, 77 ′, and the main pressure oil supplied to the working hydraulic actuator, for example, the dozer cylinder 8, is supplied by the swivel joint 36 and the traveling motors 6 _L , 6
_R (64-57 _L ), (64'-57
_R ), the air is supplied through the flow dividing valve 44 which can switch the flow dividing. And in the above case, the flow dividing valve 44,
In addition, the dozer switching valve 37 for controlling the dozer cylinder 8 is arranged on the lower traveling body 1, but is arranged near the swivel joint 36 as shown in FIG. Also the travel motor is formed in the swivel joint 36 6 _L, 6 _R for supply and discharge passages 64,77,64 ',
As an oil passage other than 77 ', the pilot pressure passage 60 for applying respectively to the pilot port 50 _L, 50 _R of the pilot port 62, and the dozer switching valve 37 of the select switching valve 45 of the diverter valve 44, 73,7
3 ′ and a tank communication passage 71 for returning oil to the oil tank 54 provided in the upper swing body 3.

Next, the operation of the undercarriage 1 of this embodiment will be described. In the present embodiment, the swivel joint 3
The main pressure oil supply passages having a relatively large cross-sectional area (the cross-sectional area of the oil passage but not shown) passing through the main motor 6 _L include supply / discharge passages 64, 77, 64 ′ of the traveling motor 6 _L. ,
Since only 77 is provided, the space occupation of the swivel joint 36 with respect to the vehicle body can be set to a minimum, and the manufacturing cost of the swivel joint 36 can be reduced. Further, since the flow dividing valve 44 and the dozer switching valve 37 for controlling the dozer cylinder 8 are arranged on the lower traveling body 1, piping between the two valves 44, 37 and the swivel joint 36 (pipe shown in FIG. Road 6
5, 65 ', 68, etc.), a compact connection arrangement can be achieved, and the equipment layout and maintenance of the upper swing body 3 can be performed with a margin. In addition, the supply / discharge passage 6 for the traveling motors 6 _L and 6 _R
The oil passages other than 4, 77, 64 'and 77' include the pilot port 6 of the selection switching valve 45 in the flow dividing valve 44.
2, and the pilot port 5 of the dozer switching valve 37
A pilot pressure passage (shown in FIG. 2) having a relatively small cross-sectional area (a cross-sectional area of an oil passage but not shown) for acting on O _L and 50 _R , respectively, and an upper revolving unit 3 are provided. Since the tank communication passage 71 (shown in FIG. 2) for returning the oil to the oil tank 54 is formed, the swivel joint 36 can be made to have a compact shape.
The switching operation of the dozer switching valve 37 can be easily performed without any trouble.

[0012]

In the undercarriage of the construction machine of the present invention, only the supply / discharge passage for the traveling motor is provided as the main pressure oil supply passage having a relatively large cross-sectional area passing through the swivel joint. The space occupation of the joint in the vehicle body can be set to a minimum, and the manufacturing cost of the swivel joint can be reduced. Further, since the pressure oil dividing means and the directional control valve for the working actuator are arranged on the lower traveling body, the piping connected to the swivel joint can be shortened, and a compact coupling arrangement can be achieved. Layout and maintenance can be performed with a margin. In addition, since the passage for passing the swivel joint in a passage other than the supply / discharge passage for the traveling motor is, for example, a pilot pressure passage or a drain passage having a relatively small cross-sectional area, the shape of the swivel joint can be made compact. The switching operation of the directional control valve for the working actuator can be easily performed without any trouble. Therefore, in the construction machine having the undercarriage according to the present invention, the structure of the swivel joint can be simple and small, and the layout and maintainability of hydraulic equipment mounted on the vehicle body can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a hydraulic excavator having a lower traveling body according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram of the hydraulic shovel in FIG.

FIG. 3 is a plan view of a main part of an incision showing a lower traveling body of the hydraulic shovel in FIG. 1;

FIG. 4 is a hydraulic circuit diagram of a wheel type excavator according to one embodiment of the prior art.

FIG. 5 is a partially cutaway front view showing a relationship between an operation lever serving also as a prior art for operating a handbrake and a switching valve in FIG. 4;

[Explanation of symbols]

1 undercarriage 2 hydraulic excavator third upper turning body 6 _L, 6 _R traveling motor 8 dozer cylinder 22, 36 swivel joint 37 dozer switching valve 39 _L, 39 _R travel directional control valve 40, 41 first, second pump 43 Pilot pump 44 Divide valve 49 Hydraulic remote control valve for dozer 51 Electromagnetic switching valve for dozer work mode command 54 Oil tank 60, 73, 73 'Passage for pilot pressure 64, 64', 77, 77 'Supply / discharge passage for traveling motor 71 Tank communication oil passage

Claims (2)

[Claims] An upper revolving unit is connected to an upper portion of a lower traveling unit, and a traveling motor and a working hydraulic pressure are provided on the lower traveling unit via a swivel joint with hydraulic oil from a hydraulic pump mounted on the upper revolving unit. In a construction machine adapted to supply to an actuator, a supply / discharge passage for a traveling motor that communicates the swivel joint and the traveling motor, a pressure oil dividing means provided in the supply / discharge passage for the traveling motor, A lower traveling body of a construction machine, comprising: a work actuator supply / discharge passage communicating the flow dividing means with the work actuator. 2. The undercarriage according to claim 1, wherein the pressure oil diverting means and a work actuator direction switching valve provided in the work actuator supply / discharge passage are arranged on the lower traveling body. Undercarriage of construction equipment.